Presentation on basics of computer programming and programming Raspberry Pi's using the Python Programming Language at the Raspberry Pi Demo Day at Toronto Reference Library on May 28, 2016.

1. Pi Is For…
Programming
In
Raspberry

2. Computers Don’t
Do Anything
Without
Instructions

3. Programming, or
Coding, is how we
tell computers what
to do using
instructions that
the computer
understands.

4. What Is A Computer Interface?

5. Jacquard Loom Interface - 1801

6. Switch Computer Interface - ENIAC 1945

7. 1950’s - 1960’s Business
No Command Line Interface
1990’s Personal
Graphical User Interface (GUI)
Command Line Computer Interface
1970’s Personal
Command Line Interface Only
(Sometimes called Shell Or Console)

8. Python Uses A Command Line Interface?

9. ARM Cortex-A53 CPU
How Does Programming Work?

10. Hardware Specific, Very Fast But
Very Difficult For Human
Comprehension. This Is The Language
That The Computer Speaks.
ARM Cortex-A53 CPU
How Does Programming Work?

11. How Does Programming Work?
ARM Cortex-A53 CPU

12. Hardware Specific, Very Fast And
Somewhat Comprehendible For People.
ARM Cortex-A53 CPU
How Does Programming Work?

13. ARM Cortex-A53 CPU
How Does Programming Work?

14. High Level Languages Are Considered
Cross Platform and Comprehendible.
To Maintain Speed They Compile An
Assembly Or Machine Language
Version Of The Code Specifically
For The CPU.
ARM Cortex-A53 CPU
Quality Compilers Can Generate Quicker Code
C Often Used In Graphics and Operating Systems
How Does Programming Work?

15. ARM Cortex-A53 CPU
Quality Compilers Can Generate Quicker Code
C Often Used In Graphics and Operating Systems
How Does Programming Work?

16. ARM Cortex-A53 CPU
PYTHON BASIC
Dynamic high-level general-purpose
scripting languages (such as Python
and PERL) execute programs in real
time using pre-compiled API’s or
machine code. Their advantage is
that programs can be be constructed
from pre built blocks and combined
into complex programs.
PERL
Software Intermediary
How Does Programming Work?

17. How Does Programming Work?
ARM Cortex-A53 CPU - Linux
PYTHON CODE
Python Virtual Machine
Bytecode

18. How Does Programming Work?
PYTHON CODE
ARM Cortex-A53 CPU - Linux
Python Virtual Machine
AMD Athlon™ X4 CPU - Windows
Python Virtual Machine
Intel® Core™ i7 CPU - MAC OSX
Python Virtual Machine

19. Hello world! In Machine Code
Why Python?

20. Why Python?
Hello world! In Assembly Language

21. Why Python?
Hello world! In BASIC, C and Python

22. Why Python?
● Python Is A General Purpose Language
○ Many computer devices
○ Libraries for most applications.
● Large Standard Code Library
○ Standard Library runs on Raspberry Pi or CRAY Supercomputer.
● Can Be Compiled To Machine Language
○ Cython compiles Python code To C.
● Can Call C Code
○ Python ctypes
● Clean code
○ Employs indentation
○ No {..code in here..} or <div>..or stuff in here..<div>
● Libraries, Libraries, Libraries
○ The secret power of Python
○ 67,000 libraries (Jan 1, 2016)

23. Getting Started On Raspberry Pi
● https://www.raspberrypi.org/documentation/usage/python/
○ RUNNING PYTHON ON A RASPBERRY PI
○ INDENTATION
○ VARIABLES
○ COMMENTS
○ LISTS
○ ITERATION and RANGE
○ CREATING/SAVING PYTHON FILES
○ EXECUTING PYTHON FILES

24. Python Interactive Mode
Python Shell
Command Line Interface
Python Prompt
>>>
Getting Started On Raspberry Pi

25. Python Interactive Mode
Getting Started On Raspberry Pi

26. Getting Started On Raspberry Pi
Python Interactive Mode

27. Getting Started On Raspberry Pi
Python Run Module

28. Getting Started On Raspberry Pi
Python Run Module

29. Getting Started On Raspberry Pi
Python Run Module

30. Getting Started On Raspberry Pi
Python Run Module

31. CODE
https://trinket.io
Programming In Python - Overview

32. CODE
RESULT
(CONSOLE OUTPUT)
https://trinket.io
Programming In Python - Overview

33. https://trinket.io/python/81bea2e14c
Python Sequence Code

34. https://trinket.io/python/81bea2e14c
Python Sequence Code

35. https://trinket.io/python/883c20b4a3
Python Functions Code

36. https://trinket.io/python/883c20b4a3
Python Functions Code

37. https://trinket.io/python/883c20b4a3
Python Functions Code

38. https://trinket.io/python/81bea2e14c
Python Functions Code

39. https://trinket.io/python/883c20b4a3
Python Functions Code

40. • Python runs as a minimum with always available “built-in
libraries”.
• Libraries provide the code functionality
Python Built-In Libraries

41. https://trinket.io/python/df57cd9d6f
Python Import Standard Libraries

42. https://trinket.io/python/df57cd9d6f
Python Import Standard Libraries

43. Python Object Oriented Code

44. OBJECT
Python Object Oriented Code

45. OBJECT
PROPERTIES
Python Object Oriented Code

46. Python Object Oriented Code

47. https://trinket.io/python/a9a6112ca5
Python Object Oriented Code

48. https://trinket.io/python/d4e0f1f07d
Python Object Oriented Code

49. Python “Clean” Code

50. Python “Clean” Code
Indentation
and levels
used as
separators in
code. No curly
braces or
containers.

51. Python “Clean” Code
Minimal use of
colons, semi-
colons, etc.

52. External Libraries - Wikipedia
The Beatles Wikipedia Page

53. External Libraries - Wikipedia
Packages Located In The Python Package Index
(PyPI)

54. External Libraries - Wikipedia
Use Raspberry Pi Terminal To Install External
Libraries Using PIP

55. External Libraries - Wikipedia
“sudo pip install wikipedia” In Terminal Installs
The Python Wikipedia Library On Your Raspberry Pi

56. External Libraries - Wikipedia
Estimated 67,000 Libraries (Jan 1, 2016)

57. Review

58. Review
PYTHON CODE
ARM Cortex-A53 CPU - Linux
Python Virtual Machine
AMD Athlon™ X4 CPU - Windows
Python Virtual Machine
Intel® Core™ i7 CPU - MAC OSX
Python Virtual Machine

59. Review

60. Review

61. Review

62. Review

63. Review

64. Review

65. Review

66. Review

67. Review

68. Review

69. Contact